The present invention relates to the of field of water treatment and, more particularly, to systems for the purification of drinking and other water for use in homes as well as small office and commercial applications.
Purification contemplates a broad-range of technologies that necessarily address an equally broad litany of water quality problems. Often resort must be made to multiple technologies in furtherance of an overall water quality objective. The present invention falls within this latter category.
Purification issues range from the merely cosmetic--does the water look pure--to the health-compromising--does the water contain typhoid, dysentery, or other potentially harmful bacteria. And in between, there is the panoply of aquatic aggravations which, while non-lethal, often constitute more than minor annoyances. This latter group includes mineral-laden hard water (e.g. calcium and magnesium) and water with its own unique attributes of taste and smell (e.g. the hydrogen sulfide `rotten egg`).
Most commercially available home and small office water `treatment` devices, including conventional water softeners and the plethora of activated charcoal and similar filters, have been largely directed to the water aesthetics arena. In short, these systems are designed to treat purification issues in connection with existing potable water supplies.
Water aesthetics is certainly not a trivial concern. Yet in recent years the focus has enlarged. Drinking water quality has become an increasing obsession for many homeowners even where the existing tap water supply (well or municipal) meets or exceeds minimum health standards. Mere `pretty` or `safe` water may no longer be sufficient. Bottled drinking water, therefore, has become increasingly popular--although its inconvenience and cost make it less than the optimal solution. The better long-term solution is the addition of permanent, on-site filtration or purification apparatus.
The present invention falls within this latter category of permanent, but after market apparatus directed to the further conditioning of water both for aesthetic as well as health reasons. Significantly, the present system may be employed not merely to improve the purity of certified `safe` water supplies (i.e. in lieu of bottled water) but, in many areas, to condition otherwise non-potable water--rendering it safe for human consumption.
The present apparatus combines plural technologies in a unique arrangement that minimizes the overall size and complexity of the equipment required to achieve these stated purification goals while doing so in a manner that is substantially less expensive, cumbersome, and ungainly than the prior `plumbed-together` collection of otherwise unrelated, independent purification sub-systems. These are important considerations in the home and small commercial environment where cost, required space, and sightliness are all factors to be weighed in selecting an overall water purification approach.
In the preferred embodiment, the present system employs a preconditioning stage that serves, in its own right, to remove or reduce unpleasant taste and odors, chlorine, pesticides, THM's, PCB's, and a variety of other chemicals not uncommonly found in water supplies, some potentially carcinogenic. Secondly, by reason of this preconditioning, suspended particulate and other chemical matter that might otherwise literally block the effectiveness of the subsequent disinfectant stage, are removed.
A variety of preconditioning stage sub-systems are contemplated hereby--the actual choice of filtering or other purification being determined by site-specific issues, i.e. the specific content or constituents of the water sought to be processed. Often, a filter comprising a bed of steam activated carbon is provided and sufficient. Alternatively, a conventional `hard-water` softener may be employed.
Ultra-violet irradiation ("UV") forms the heart of the bacteriological purification, or follow-on, stage of the present apparatus. But, as noted, the efficacy of UV irradiation may be compromised, in the absence of the preconditioning stage, as contaminants may literally block full UV illumination of the water flowing past the lamp UV source.
The use of UV biological sterilization in combination with preconditioning filter equipment is not, itself, new. However, the conventional trade `wisdom` has been to plumb-together, in cascade, existing and independent subsystems, such as activated charcoal filters, softeners, and/or UV or other sterilization equipment. While such combinations perform acceptably, they suffer the above-discussed shortcomings as to size, ungainliness, and, most importantly, the higher costs not-unexpectedly associated with the failure to take advantage of the efficiencies that accrue by an inventive integration of sub-technologies.
One such extravagance found with conventional cascade technology is the UV vessel, itself, which vessel must remain uncontaminated, as noted, to assure irradiation of all water flowing therethru. To achieve this desired level of continuing purity, polished stainless steel pressure vessels are commonly used. The stainless `pressure` vessel must be designed to withstand up to 150 psi to accommodate the full range of standard water distribution pressures that may be encountered. It will be appreciated that elimination of the `pressurization` requirement in connection with the stainless UV vessel represents a significant structural advantage both as to gauge (i.e. weight) and cost thereof.
The present apparatus achieves this goal by advantageously locating the UV vessel within a larger chamber, the latter chamber being pressurized to full system operating pressure. In this manner the UV vessel operates with a net-zero differential pressure (i.e. `inside pressure` minus `outside pressure`). At first blush this use of a secondary, outer pressure chamber might seem an extravagant and even more expensive means of eliminating the pressurization requirement of the UV vessel.
This would undoubtedly be true but for the fact that a pressure chamber is required in connection with the above-discussed preconditioning stage. The present invention advantageously integrates the UV subsystem within the preconditioning stage pressure chamber thereby, in essence, utilizing the preconditioning pressure chamber in a dual capacity--an efficiency utterly unknown to conventional cascade technologies.
Thus, the present invention contemplates but a single visible chamber substantially similar to the single tank that defines most existing filters. That there is a second vessel associated therewith is not, from a space and aesthetics perspective, apparent. Also `absent` is the ungainly piping otherwise required to functionally plumb and interconnect multiple pressure chambers.
A coaxial arrangement is employed whereby the now, un-pressurized UV chamber is oriented along the longitudinal axis of the preconditioning pressure chamber. This coaxial arrangement is particularly advantageous by reason that a typical UV chamber need be of comparatively narrow diameter in order to assure that the entire water `column` becomes properly irradiated (UV absorption and dispersion limit the effective `thickness` of the water through which the UV may pass thereby correspondingly limiting the diameter of the UV vessel). Therefore, the placement of the UV chamber at the center of an otherwise conventional filter or softener pressure chamber or tank does not substantially lessen the cross-sectional area available for the preconditioning function. The preconditioning tank may be of any conventional fabrication, for example, fiberglass reinforced plastic.
A multipurpose inlet/outlet head is screwably fitted to the top of the preconditioning tank. This head serves not only to receive and distribute the inlet water across the top of the charcoal or other active medium in the preconditioning portion of the pressure chamber, but to channel the preconditioned and sterilized water effluent from the tank after it has been fully treated. Further, this head must provide a means for integrating and attaching the stainless UV chamber, the UV lamp; and the quartz tube that protects the UV lamp. And, yet further, this head must accommodate a `sight means` for visually verifying operation of the UV lamp as well as a mechanism for removing the lamp for replacement, and the quartz tube for cleaning--all while maintaining proper pressure seals against the leakage of the pressurized water therefrom.
More specifically, the present head defines a multichannel/multi-port arrangement having a first fluid passage defined through and along the central axis of the head. A first port in fluid communication with this central passage serves as the actual water effluent interface from the present purification system. The stainless UV chamber is threadably interfaced to the lower portion of this central passage thereby rigidly mounting the chamber (to the head and pressure chamber) and providing a fluid path for the sterilized water from the UV chamber to the effluent port. A UV sight-gland is similarly screwably threaded to the top opening of the central passage and serves to physically lock the quartz tube in place and as a sight for confirming UV tube illumination.
A second passage or channel, in fluid communication with a second or inlet port, is provided in the head. This passage channels or sprays the incoming water around the inside periphery at the top of the pressure tank whereby the incoming water is distributed over the active filtering or other medium within the preconditioning portion of the present system. Thus, it will be appreciated that both inlet and effluent connections are made to the upper part of this single pressure chamber and, more specifically, through the above-described multifunction interface head.
The stainless UV vessel is dimensioned such that its lower distal end is spaced above the bottom of the pressure chamber approximately four inches. While it should be appreciated that other spacing dimensions may be used, this dimension has been found to be sufficient to allow placement of a UV vessel inlet filter at the lower end of the stainless UV vessel. This filter serves to segregate the first preconditioning chamber from the second, coaxially positioned UV sterilization vessel by literally blocking egress of the active medium from the first chamber into the UV vessel.
It is therefore an object of the present invention to provide a compact and comparatively inexpensive water purification system for home, small business or commercial use. A further object is to provide for water sterilization. Yet another object is to provide water preconditioning prior to sterilization. It is an object of the present invention that such preconditioning may be combined with the sterilization to minimize the number of pressure vessels required. It is an object of one embodiment of the present invention that UV irradiation shall be used for sterilization. It is therefore a further object that a non-pressurized stainless steel UV vessel be employed. And it is yet another object that such vessel be positioned within a pressure chamber which will therefore serve a dual capacity of providing water preconditioning and as a pressure housing for the the UV vessel. In one embodiment it is an object that a multifunction/multi-port head be fitted to the top of a single chamber. It is an object that the head provide an inlet and means for applying the inlet water onto the upper portion of filtration media within the single chamber. It is an object that the head provide an second effluent port, not in fluid communication with the inlet port, to receive sterilized and processed water from the chamber. Further, it is an object that the head include means for affixing a UV vessel thereto in fluid communication with the effluent port and means for accessing the UV lamp and protective quartz tube or sleeve associated therewith. It is an object of the present invention that the chamber include means for segregating the preconditioning portion of the system from the sterilization portion whereby charcoal or other active filtration media associated with the preconditioning portion of the system are prevented from entering the sterilization portion. These and other objects will become apparent from the drawings and specification which follow.